applicator Flashcards
Annual and perennial weeds in corn, soybeans, and grain sorghum fields are considered a continual problem and are difficult to control with herbicides.
False
Shattercane and Johnsongrass are forage-type sorghums that are probably the most troublesome weeds in
grain sorghum
Once the seedbed is prepared… the main reason for tillage is
weed control
No till crop systems rely heavily on herbicides to control weeds.
True
Cultivation becomes difficult in soybeans when the row widths are less than _________________ inches.
20
will typically result in poor activation of soil applied chemicals.
Lack of rainfall
A 100% no till system will have ____________________________ perennial weeds as compared to fields that use reduced tillage systems.
less
Which of the following are insect pests that can be a problem in Missouri Corn
European Corn Borer Fall Armyworm Black Cutworm Corn Earworm Southwestern Corn Borer
___________________ suck the juices from grain sorghum with their piercing -sucking mouthparts.
Chinch bugs
Insects are considered a major problem to producers that grow soybeans in Missouri.
False
Which of the following are considered occasional insect pests of soybeans?
Green Cloverworm Corn Earworm Grasshoppers Seed Corn Maggot Soybean Thrips
Seed rots in corn occur ___________________________ germination.
before
Rots and blights in corn are more severe in __________________________ conditions.
wet
Which of the following is not a good management practice when trying to prevent corn rot and blight?
Planting when temperatures are below 50-55 degrees F
Which of the following are good practices for management of corn foliage diseases?
Planting disease resistant corn hybrids
Rotating crops with at least one year out of corn
Managing corn residues
Applying foliar fungicides if warrented
Corn that is stressed by poor growing conditions such as: lack of moisture, poor fertility, or additional stresses is more likely to be damaged by nematodes.
True
Stalk rots become a problem when plants are stressed during the ____________________________ stage of development.
grain filling
Corn can get kernel rots from fungi while it is in the field or when it is in storage.
True
Nematodes cause damage to corn by
feeding on the root
What size are nematodes?
microscopic
Foliage diseases of Sorghum usually favor which of the following conditions?
Warm Temperatures
Wet Weather
High Humidity
Which of the following is not a foliage fungal disease that affects sorghum in Missouri?
Pythium
Root and stalk diseases of grain sorghum usually occur at what time and stage of plant development?
Late season as plants are maturing
General symptoms of early season soybean diseases range from seed decay, pre- or post-emergence damping off, and/of wilt and death of established seedlings.
True
Soybean diseases can be caused by fungi, bacteria, or viruses.
True
Pythium, Phytophthora, Rhizoctonia, and fusarium diseases are all diseases that cause problems in the _________________________ season.
early
Septoria brown spot, bacterial blight, downy mildew, and powdery mildew are all examples of ______________________ diseases of soybeans.
foliage diseases
Bean pod mottle, soybean mosiac and tobacco ringspot or budlight are all examples of _______________________ diseases of soybeans.
viral
Soybean cyst nematode affects soybeans in _________________________ season.
mid-late
Soybean cyst nematode, charcoal rot, pod and stem blight, anthracnose, stem canker are all examples of ________________________ season diseases in soybeans.
late
Cotton requires very few herbicide applications or cultivation
false
There are _________________________________ herbicides that are available and registered for weed control in cotton.
very few
Over the top herbicide applications are difficult so _______________________ applications are often used.
directed
It is important that weeds get taller than the cotton so that treatment of them is easier.
false
Spraying insecticides on cotton are rarely needed.
false
Bacterial blight and several fungal leaf spot diseases are common foliage diseases of cotton in Missouri.
true
Verticillium wilt and Fusarium wilt are are both common wilt diseases of cotton.
true
Nematodes do not cause damage to cotton
false
Nematodes cause damage to cotton by
feeding on roots
Which of the following is the cause of boll rot?
fungi
Rice weed control is much the same as weed control of corn or soybeans.
false
Why is rice flooded?
weed control
______________________________________ is one of the most prevalent and yield robbing weeds of rice.
barnyard grass
Which of the following is a common insect pest in rice?
Rice water weevil
Rice stink bug
Grasshoppers
Winter wheat is a competitive crop that tends to suppress dense stands of many weeds.
true
What stage of wheat growth is wheat the most tolerant to herbicide applications?
When the length of the leaf sheath exceeds 2” but not more than 4” above the soil surface
Which of the following describes problems associated with weeds in forage crops?
Weeds are sometimes lower in protein
Weeds are less palatable to livestock
Weeds can be poisonous to livestock
Which of the following is NOT a good management practice when trying to prevent weeds in forage crops?
Maintain a Low pH
Established hay crops such as alfalfa, clovers, and alfalfa grass mixtures tend to be most prone to weed infestations during what time of year?
winter
Alfalfa weevil damage tends to begin around early March (southern Missouri) and April (Northern Missouri).
true
Potato leafhopper damage in alfalfa tends to happen to which cutting?
2nd and 3rd cutting
What is considered the biggest problem with the striped blister beetle in alfalfa.
infested hay is toxic to horses
The principal cause of seedling, foliage, and root & crown rot diseases is _________________________________.
fungi
_____________________________________ weed species can be particularly troublesome in established orchards due to the lack of soil disturbance which allows their establishment and spread.
Perennial
Trees that are maintained in a weed free environment produce more fruit as a result of increased fruit set and size.
true
Most diseases of fruit are caused by______________________________
fungi
Compared to field crops there are many more herbicides that are labeled for vegetable production.
false
There are _____________________ registered herbicides for postemergence weed control in vegetable crops.
few
Because vegetables are annual crops and can be tilled several times per season, _______________________________ weeds tend to be the weeds that cause the most problem.
annual
Which of the following are problems that weeds cause in tobacco operations?
ower yield and quality
Increased production cost
Interference with harvesting
Increase in the spread of diseases through cultivation
Serve as alternate host for for disease organisms
